The overall goal of this project is to study how cytotoxic T lymphocytes (CTL) recognize antigens on the surface of SV40-transformed mouse cells. The technique of growing effector lymphocytes at clonal levels, together with the use of H-2 variants and SV40 deletion mutants produced by gene manipulation, provides a powerful tool to elucidate the immune recognition of SV40-transformed cells by H-2-restricted CTL. We intend to identify the region(s) of the class I H-2 antigen-restricting element using H-2Kb-restricted CTL cloned cell lines and a target cell panel consisting of the spontaneously arising Kb mutants and a series of chemically induced somatic cell variants with altered Kb. These new Kb somatic cell variants have been partially characterized with a series of monoclonal anti-Kb antibodies and their genomic DNA is being sequenced. We also intend to map the portion(s) of the SV40 T antigen which is expressed on the cell surface and is immunologically recognized. In this work, we will make use of monoclonal antibodies, which will be mapped to distinct epitopes of the SV40 T molecule and a transforming SV40 deletion mutant which produces truncated T antigens. We will continue to produce monoclonal antibodies to mouse SV40 transformants to optimize chances of obtaining relevant antibodies that detect T antigens on the SV40-transformed cell surface. This structure-function analysis is designed to provide information about the immune recognition of SV40 TSTA and the involvement of H-2 in CTL recognition and may ultimately lead to methods of manipulating the host immune response to control tumor growth. (AG)